Fig. 4.

Representation of convergent recombination in the TRBV1/TRBJ2-1 naïve CD8⁺ T-cell repertoire. Convergent recombination is illustrated for the amino acid sequence CTCSAGNYAEQFF, which was detected in seven aliquots in mouse 1 and in six aliquots in mouse 2. (A) This TCRβ clonotype was encoded by a total of eight different nucleotide sequences across both repertoires. One possible alignment with TRBV1 (blue), TRBD1/TRBD2 (pink), and TRBJ2-1 (green) genes involving the minimal number of nucleotide additions (black) is shown. (B) At a second level of convergent recombination, multiple recombination mechanisms with similarly low numbers of nucleotide additions can produce the same nucleotide sequence. This is shown for one of the nucleotide sequences (red box) encoding CTCSAGNYAEQFF. (C) The mouse TRB gene sequences used.